Add quadrature encoders to your 20D mm metal gearmotors (extended back shaft version required) with this kit that uses a magnetic disc and Hall effect sensors to provide 20 counts per revolution of the motor shaft. The sensors operate from 2.7 V to 18 V and provide digital outputs that can be connected directly to a microcontroller or other digital circuit. This module is compatible with all of the dual-shaft 20D mm metal gearmotors we carry.